Just these 2. They're cute. But, their characters seem to be very deep, which makes them both very interesting, and somewhat human. But, both are still mysteries, because the authors haven't gotten to their stories yet.

So, where they're from, and what they're about, we don't know yet. We just see some of their personality in the current story-line, and both seem very conflicted.

And, despite the fact they come off as, evil in Ginjou's case, and asshole-ish, in Cross' case, they're hinted in scenes, to be very caring characters. Ginjou's vengeance changed him, and made him colder and calculating, Cross is just hardened from war, and losses.